How to add a 4Way Switch

How to Add a 4Way Switch with Other Light Switches: I need help adding a 4-way switch in my home.

Wiring a 4Way Light Switch with 3Way SwitchesElectrical Question: I need help adding a 4-way switch in my home.

I’m looking for help and diagram for adding a 4-way switch in my home.

I have some experience with basic wiring but 3-way and 4-way switches can be confusing.

The additional switch will be used for my basement light circuit.

I want to add a switch at the bottom of the basement steps.

The Current setup with two 3-way switches

Switch #1

Is located at the top of the steps.

The power source feeds into this switch box.

The feed to the lights is from the switch box.

Switch #2

Far side of basement.

Just a switch fed from switch #1.

This home electrical wiring question came from Gary, in Rumney, New Hampshire.

Dave’s Reply:
Thanks for your electric wiring question Gary.

Adding a 4Way Switch to Two 3Way Switches

Application: Wiring a 4-Way Light Switch.
Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrician.
Tools Required: Basic Electricians Pouch Hand Tools and Power Tools for installing electrical wiring, and Voltage Tester.
Estimated Time: Depends on personal level experience and ability to work with hand and power tools.
Precaution: Identify the lighting circuit, turn it OFF and Tag it with a Note before working with the wiring.
Notice: Installing additional 3-way or 4-way switch wiring should be done according to local
and national electrical codes with a permit and be inspected.

Wiring a 4-Way Switch in with two 3-Way Switches

In some areas of the home we may need more than two light switches, especially in long hallways with multiple entryways. This is an example where one or more 4-way switches may be installed.

In this application where two 3way switches already exist, a 4way switch may be added by simply installing two 2-wire with ground cables of the same wire gauge as the circuit wiring from either of the 3way light switches to the location of the new 4way switch.

A 4way switch has two marked sets of screw terminals where the two wires of each 2-wire cable will attach.

The 2-wire cables intercept the two traveler wires at the 3way switch location which are located at one end of the 3way switch.

The two 2-wire cables are basically creating a loop of the pair of traveler wires through the 4way switch.

Marking or identifying the white wires of the 2-wire cables as black or red is required to indicate that the wires are being used for switching, and be sure to ground the light switch.

Fully explained 4 way switch diagrams. 4-way switches are a convenient way to operate lighting fixtures from three or more locations.
The electrical wiring adds additional wiring to the same principles of 3-way switching.

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